Magnetic reconnection and physical processes

[sol invictus]

Ok I was wrong the whole idea of fields being non physical is not at all relevant to the discussion at hand however.

Address the relevant material at your will.

I'm not sure what to address that hasn't already been addressed many times over.

Magnetic reconnection, meaning any magnetic field configuration that changes with time in such a way that the field lines break and re-connect, is a perfectly consistent and physical solution to Maxwell's equations. Contrary to your (past) claims it does not violate Gauss' law for magnetism. We've given you such solutions explicitly, and explicitly verified for you (since you're not capable of doing it yourself) that they satisfy all of Maxwell's equations.

Magnetic reconnection in realistic plasmas is a more complex and rich topic. But we've linked to simulations of Maxwell in plasma that plainly show energy being released and plasma being flung out to the sides as the field lines reconnect and snap back, and we've linked to the websites of multiple experiments that have observed that same phenomena in the lab.

I'm not sure what more there is to say beyond that, so I'll stop here.

 

[GeeMack]

Evidently he only discusses people, not scientific topics.

It's not the people, it's the position they take and their method of presenting it. Of course all you've offered for the last several years are your incessant arguments from incredulity and ignorance, a lot of whining and bitching, and a seemingly endless barrage of unsupported assertions. Nothing about your position is quantitative. Legitimate science is. So while you may be jabbering about science topics, you're certainly not being scientific. Pretty much everyone else here realizes that, too. It surely hasn't escaped your notice that the majority of replies to your nonsense are people telling you you're wrong.

There are several articulate intelligent people in these discussions. I first read Tim Thompson's EU material on the web maybe a decade ago, and it's been years since Neried put most of your crackpot notions to rest over at the BAUT forum. I can't do any better than they are in this conversation. These good people don't need my help to show how you've failed in every way to support your position.

Besides, I did my part many years ago when I shredded your insane solid surfaced Sun conjecture to little pieces. And you see how well it worked? When anyone brings it up you change the subject so fast you can almost feel that solar wind whooshing past. You're not willing to face the embarrassment of talking that crap on a public forum anymore.

 

[brantc]

The magnetic field gets its "instantaneous energy" from the energy stored in the magnetic field. It is basic electromagnetism that magnetic fields contain energy.
Where the magnetic field gets the energy that is stored in it depends on what creates the magnetic field. For example:

• In the magnetic reconnection experiments in labs, from the electric currents running through the magnets.
• In the Earth's magnetosphere, from the origin of the Sun's magnetic field (thought to be from the motion of plasma in the Sun).
• In solar flares, usually from the creation of coronal loops within the solar body before they well up through the photosphere.

Everything that you have listed can be traced to the flow of electrons.

Moving electrons make a magnetic field. The plasma lifting off from the surface of the sun is moving electrons which create a constricting magnetic field around it forming a flux tube.

There has to be some reason why the electrons stream from a location form a flux tube. Its not the magnetic field twisting from turbulence(MHD)..

If there are flux tubes outside then there are most likely flux tubes inside.

 

[brantc]

(I asked brantc to calculate how much plasma is needed "circuling perpendicular to the field" to create said field, but he does not answer,

Can you please rephrase the question. What exactly do you want to know?

 

[brantc]

Seems like Akasofu not only wants to start physics from start, he also seems unaware of a lot of old solar physics, e.g. early models of magnetic arcades and the currents etc. for example the models by Kuperus and van Tend, no need to go to Choa and Lee.

I like the part where they say:

"A major question is how the filamentary current increases. This is only possible through changes at the photospheric level. These changes can roughly be divided into:
(a) Magnetic flux variation (e.g. emerging flux);
(b) motion of field line footprints"

Even they recognize that the current increases. Probably by measuring the magnetic field.
But instead of saying that the increase is due to an increase in the flow of electrons they sat that the magnetic field must get is energy from "Magnetic flux variation (e.g. emerging flux); motion of field line footprints" (sic)which increases the the flow of electrons or plasma through the flux tube.

Not only that they use fluid terminology like tearing and turbulence instead of instabilities. And current sheets that roll themselves up into flux tubes.

You can trace faulty cause and effect MHD logic all the way back to the beginning.

 

[Reality Check]

Is ben m's guess at what you mean by "circuit energy" right

And those "current carrying" magnetic flux tubes are also known as "magnetic ropes". They carry "current flows" from one point to another. These currents can even create "z-pinches" inside those "ropes". These are current carrying filaments, large scale cousins of current carrying filaments inside an ordinary plasma ball. The "circuit energy" of both circuits will determine the outcome at the point of "circuit reconnection".

That is right: magnetic ropes in a plasma create currents in the plasma. In fact any moving magnetic fields in a plasma create currents.
But yuor ignorance continues:

• Magnetic ropes are not "current carrying filaments". The plasma that they are in experiences currents.
• Magnetic ropes have nothing to do with current carrying filaments inside an ordinary plasma ball.
• You have yet to define "circuit energy".
• You have yet to define "circuit reconnection" except vaguely (post to come).

First asked 30 January 2010
Michael Mozina,
Is ben m's guess at what you mean by "circuit energy" right?

Eureka! I may have made a breakthrough. Enough of a breakthrough that it's worth dipping back into this thread for one post after which it all goes straight back on ignore.

After a bit of reading, I have a GUESS at what MM has meant (or what Alfven presumably meant that MM is now incanting) by "circuit energy". The term "circuit energy" seems to be used (very rarely in physics, perhaps more commonly in EE?) to refer to the sum of the self-inductances and all pairs of mutual-inductances of electric currents in an array of circuits. For physicists, it's the energy in section 5.17 of Jackson. It allows you to calculate the energy if you know the currents in a set of circuits, and the inductances of and between all circuits (!) but don't want to calculate the magnetic field explicitly (!?!).

And Jackson section 5.17 is devoted to proving that this inductive energy is exactly the same as the energy you found (in section 5.16) by integrating 1/(2mu0) B^2 over space.

So: it's rather silly that MM has been promoting "circuit energy" as the a matter of central importance to plasma physics, then crying foul/error/balk when anyone invokes "energy stored in a B field". Dude, it's the same thing. And---under what circumstances do you know any mutual inductances without having calculated the fields already? Certainly not the circumstances in a solar flare where the geometry is changing.

In turn, of course, the rest of us have been pooh-poohing "circuit energy". I had a guess earlier that perhaps this is what it meant, but I rejected that guess because MM's invokations always contradicted this meaning---you always connected it to electric fields, which are completely irrelevant. I asked him directly to define it and he ignored it. But yeah, no, it turns out that "circuit energy" is not small---rather, it is what the rest of us have been talking about the whole time. It's a weird name for 1/(2mu)B^2.

It's not at all a standard term in physics, which is why no one has heard of it. Google turns it up in EE, but search for "circuit energy" +plasma and what comes up? After some mishits, it's: Alfven's book, then some 1972 paper, then MM himself on this forum. No wonder no one can understand him. Anyway, now that I understand him (if indeed I do) I can speak more clearly: MM, this circuit energy thing is exactly the same problem as the problem tusenfem has described repeatedly. If you state the magnetic field distribution---which is what solar flare modelers do---then you instantly know both the energy of this configuration (integrate B^2) and the current density that makes it (curl B). If you state the current density instead, there's a hideous, labor-intensive calculation that gives you the B fields (Biot-Savart) and an even more hideous calculation that gives you the "circuit energy" as a sum of 1/2 LI^2 terms, and even that requires an extra discretization. That's why modern physicists---the ones who need to work with actual numbers---invariably do the former and have done for decades.

Every time you state that the B-field-version is "wrong", you're stating that the circuit energy version is wrong. They're the same thing. Every time you state that B fields don't store and release energy, you're saying the same thing about "circuit energy" (assuming my definition) because they're the same thing.

 

[Reality Check]

Everything that you have listed can be traced to the flow of electrons.

Everything that I have listed can be traced to the flow of electrons creating magnetic fields but not all at the point where the magnetic reconnection happens.

• In the magnetic reconnection experiments in labs, from the electric currents running through the magnets.
• In the Earth's magnetosphere, from the origin of the Sun's magnetic field (thought to be from the motion of plasma in the Sun).
• In solar flares, usually from the creation of coronal loops within the solar body before they well up through the photosphere.

 

[Reality Check]

Michael Mozina: What is "circuit reconnection"

First asked on 19 January 2010 by Tim Thompson

What is "circuit reconnection"?
Let me start by pointing out that Mozina has never given any indication, at the level of real physics, as to what the words "circuit reconnection" (or "particle reconnection" as he sometimes puts it) are supposed to mean. If we simply look at simple electric currents, and assume that the currents merge, then what happens to the kinetic energy of the particles in the circuit? The total kinetic energy of the particles in the final merged current cannot exceed the total kinetic energy of the particles in the merging current, absent an influx of energy from other sources. That's why I have said (and Mozina has resolutely ignored) that "circuit reconnection" cannot be what's happening because it violates the well accepted principle of conservation of energy. My position may change, pending some more informative explanation of what "circuit reconnection" is supposed to mean. But see post #3209 by ben_m in the plasma cosmology thread for additional insight into currents & fields regarding circuit reconnection.

MM's first attempt which has no actual physics in it:

It's a "short circuit" between two current carrying "magnetic ropes". Is that clear enough?

My reply

I think that is clearly not clear enough.

• What is a "short circuit" and how does it differ from a short circuit or the merging of two electric currents?
• What are "magnetic ropes" and how they differ from say magnetic flux.
• How do the "magnetic ropes" ropes carry current?
• What is the mathematical relationship between the properties of the "magnetic ropes" and the current that they carry?
• Where does the energy come from in the "short circuit" that is detected in magnetic reconnection?
• How much energy is released in the "short circuit" and how does that compare to the energy that is detected in magnetic reconnection?

You may find it easier to just cite the textbook from which you learned this concept of "circuit reconnection".

 

[Tubbythin]

Ok I was wrong the whole idea of fields being non physical is not at all relevant to the discussion at hand however.

Why bring it up then?

 

[CaveDave]

...
Numerous astronomical events that were explained by magnetic reconnection in the past are now being better explained by completely separate electrical processes.

Heres one as a minor example:

http://adsabs.harvard.edu/abs/2007ITPS...35..751A

Followed that link, which said it was an IEEE publication. There was not even an abstract, however, the second link from the top (electronic refereed journal, I think) led to this:

1. Long-Standing Unsolved Problems in Solar–Terrestrial Physics
Akasofu, S.-I.;
Plasma Science, IEEE Transactions on
Volume 35, Issue 4, Aug. 2007 Page(s):751 - 758
Abstract:

This paper is not intended for firm believers of magnetic reconnection. It calls for attention of the young generation to the following facts: (1) there are a number of unsolved problems such as sunspots, solar flares, and magnetospheric substorms in spite of almost 50 years of effort; (2) one of the reasons for this failure to solve them may be because the guiding principles in understanding those phenomena are not well founded and are misleading; (3) thus, it is encouraged to cast doubt on the leading paradigms and develop new ideas.
Abstract | Full Text: PDF(626 KB) IEEE JNL

What the hell does THAT mean?


Also, would Tusenfem or other real physicists actually respect or publish anything in an engineering journal?

Cheers,

Dave

 

[The Man]

No "reconnection" in the fields is even taking place! You could do this whole conversion of energy thing with couple of springs. Is that "spring reconnection"?

See now your starting to get the concept with the spring analogy. Yes you can do the same conservation of energy with a spring or springs and yes the spring(s) switching from resisting the sliding to pulling in the direction of sliding would require "spring reconnection".

The "ruse" here is your claim that the energy is stored in the "reconnecting" fields. It's simply stored energy in the *COMBINED* EM fields that is released again just like if we used a spring to achieve the same goal. There's no 'reconnection" taking place, just a transfer of energy back and forth, in and out of the combined fields. The term "reconnection" has nothing to do with it.

No the “ruse” is only in your imagination. The fields store energy, the fields reconnect, thus the stored energy is in the reconnecting fields and reconnected (changing the direction of the applied force by that stored energy) with the fields. Attach a spring or springs between two blocks. As you pull them apart, pulling one of the blocks toward a third block, the spring(s) will store some energy by resisting that pulling force (resulting in an opposing force). When you release the block the spring(s) will pull the one block back to the second and away from the third block (stop your applied force and the opposing force of the spring(s) remains). If while the spring(s) is stretched halfway between the second and third block the stretched spring(s) is disconnected from the second block and attached to the third (“spring reconnection”) the first block will now move towards the third block as the spring(s) releases the stored energy (what was an opposing force to your applied force now becomes a co directed force). So both with a field and with the spring(s) the energy stored resisting the applied force (by the opposing force of the field or the springs) is released as energy assisting the applied force (a co directed force) by a reconnection event (field or springs). Please remember that the reconnection event is neither the storage of the energy by the field or the spring(s) nor is it the release of the stored energy. It is specifically the reconfiguration of the field or spring(s) that permits that stored energy to be released in a manor that does not directly oppose the applied energy that was stored. To try and put it more succinctly the reconnection event redirects the force applied by stored energy in the field or spring(s) that normally directly opposes the applied force to the field or spring(s) so that it no longer directly opposes and is opposed by that applied force to the field or spring(s), thus the stored energy is able to be released while the force is still being applied to the field or spring(s)

 

[Michael Mozina]

See now your starting to get the concept with the spring analogy. Yes you can do the same conservation of energy with a spring or springs and yes the spring(s) switching from resisting the sliding to pulling in the direction of sliding would require "spring reconnection".

You're just making up words as you go now, without any regard to scientific labels. There's no "spring reconnection" involved in moving energy into potential energy and back to kinetic energy again! You might as well call a pendulum and example of "swing reconnection". Hoy. There is absolutely no connection between "magnetic reconnection" and your magnetic analogy. You're simply converting kinetic energy into potential energy and back again. It has nothing to do with 'reconnection". That's a purely contrived word and has no physical relevancy. There's no "reconnection" happening. You're simply storing kinetic energy as potential energy and releasing it again! Nothing is "reconnecting". That's a bunch of bull.

 

[Michael Mozina]

First asked on 19 January 2010 by Tim Thompson


MM's first attempt which has no actual physics in it:

You aren't even addressing the actual physics. I explained to you what "bunches' your "magnetic lines" is called "current flow". I explained that the magnetic rope contains "current flow". I explained (with that paper you keep ignoring) that these are "macroscopic circuits" and can be described that way. You're in pure hard core denial at this point.

http://arxiv.org/abs/0908.0813

The second paper on my list demonstrates that these "reconnection" events occur between two "magnetic ropes".

http://arxiv.org/abs/0908.0384

Here's how Alfven described a magnetic rope:

"However, in cosmic plasmas the perhaps most important constriction mechanism is the electromagnetic attraction between parallel currents . A manifestation of this mechanism is the pinch effect, which was studied by Bennett long ago (1934), and has received much attention in connection with thermonuclear research . As we shall see, phenomena of this general type also exist on a cosmic scale, and lead to a bunching of currents and magnetic fields to filaments or `magnetic ropes' . This bunching is usually accompanied by an accumulation of matter, and it may explain the observational fact that cosmic matter exhibits an abundance of filamentary structures (II .4 .1) . This same mechanism may also evacuate the regions near the rope and produce regions of exceptionally low densities."

Furthermore that same paper demonstrates that the energy release is *NOT* the inverted Y expected in "magnetic reconnection" theory.

Bruce long ago demonstrated that these solar events were "electrical discharges". You're simply in hard core denial now.

http://www.catastrophism.com/texts/bruce/era.htm

 

[Michael Mozina]

The fields store energy,

Yes.

the fields reconnect,

No, they simply release energy again. No "reconnection" is involved. The only thing that might and could "reconnect" are the physical magnets themselves, but that is "magnet reconnection" and has nothing to do with this topic. Quit hijacking the thread!

 

[sol invictus]

Yes.



No, they simply release energy again. No "reconnection" is involved. The only thing that might and could "reconnect" are the physical magnets themselves, but that is "magnet reconnection" and has nothing to do with this topic. Quit hijacking the thread!

I don't understand what you're objecting to, Michael. The field lines in TM's example do indeed reconnect. That's what "magnetic reconnection" means, and that's what they do.

Are you claiming the field lines don't reconnect?

 

[Michael Mozina]

I don't understand what you're objecting to, Michael. The field lines in TM's example do indeed reconnect.

Not unless the magnets themselves physically reconnect. That's magnet reconnection and has nothing whatsoever to do with solar physics.

 

[tusenfem]

Amazing. You folks insist upon math and insist upon published papers. Even when they are handed to you on a silver platter, you simply ignore them. Hoy.

That was my first impression of looking at the paper, and a lot of circuit theory on flares has been done in the late 80s and early 90s. Heck, I even did it myself (but not at the sun). So, they make more complicated circuits, so what, what exactly do you want/expect me to say about the paper.

So, the model is a magnetic loop from one polarization region to another (hey that is not what Akasofu wants us to look at!)
Flows of the plasma at the footpoints of the loop producea Lorenz force, which drives currents. Basically, shear motion of magnetic loop footpoints drive currents through the loop (Hey that is in my paper, 1993)
Then they say currents take the route of least resistance (hey I calculated plasma resistance in my paper) and the current will flow along the field.
Then they come with "if there is a connection between oppositely charged regions, possibly as a result of magnetic reconnection (sic, page 5\) a current can close the circuit through the corona. (no mention about how exactly they get there, but that is irrelevant, I think)
Then they say: "then an electric field occurs along the coronal magnetic field lines and acts on the electrons within the coronal loop and accelerates them along the field to high energies.

This is all a bit simplified but in and of itself it is correct, but it has been done much much better decades ago.

Then they come up with a complicated circuit, sure why not.
They esitmate resistivities and sizes of the loops and the velocity and magnetic field strength.
And then the estimate whether the driver (photospheric motion) generates energy enough to account for the flare energy, and yes it is enough (but also known already for decades).

Then they accelerate the electrons in the corona along the magnetic field.
The electrons are also decelerated by coulomb interactions with other electrons and protons.
If the electrons are fast enough because of a strong enough electric field (the Dreicer field) they become "run away electrons" basically collisionless and continuously accelerated.
These electrons will emit Xrays when they move through the denser chromosphere (as there they become collisional again, bremsstrahlung).

Now, I don't see what they mean with their first conclusion:
1. The energy generated by the photospheric motion is transported electrically into the corona where it is transferred into the flare. It is true that in their model it somehow gets to the corona, because the assume the current is closed there, but the "flare" part remains vague, in my opinion.I guess they are talking about the soft Xrays, but I am not sure. I guess dWs could be the power in the soft Xrays.

So, apart from using RHESSI data, I don't see very much new stuff in this paper.

 

[tusenfem]

Did you even read that paper? Did they use the term "circuit" anywhere in that paper?

Sorry, but this was not related to a paper, this was our discussion on flux tubes, plasma flow, current flow, circuits etc.

 

[Michael Mozina]

That was my first impression of looking at the paper, and a lot of circuit theory on flares has been done in the late 80s and early 90s. Heck, I even did it myself (but not at the sun). So, they make more complicated circuits, so what, what exactly do you want/expect me to say about the paper.

I want you to note that these "magnetic lines" you describe can also be described as "circuits". When they "reconnect" and they change topology like that, it's called "circuit reconnection" from the E orientation of MHD theory. That's what I want you to say.

 

[tusenfem]

My "model" is evidently exactly the same as yours. If you want to see the math describing "circuit reconnection", take your own formulas and convert them to an E orientation of MHD theory.

No it is not, YOUR model uses field lines as electrical wires.
In "my" model the ions and electrons decouple from the field (observed!) and move perpendicular to the field lines.

And I have no idea how to convert a formula to an E "orientation"